NATL: MELISSA - Aftermath - Discussion

[ljmac75]

His words to describe it. #MELISSA was the most epic chase of my career—and the most intense #hurricane I’ve witnessed.

Video from Josh of Hurricane Melissa

Now this video is the real deal. Feature length film, with some crazy winds. Past a certain point wind kinda looks the same but that screeching noise is a little worse than any other storm despite the diminishing returns. The "eye" section was a lot windier than I expected, though absolutely nothing like the proper eyewall sections. Pretty bad wind damage too, good thing he knocked on the hotel wall to demonstrate that it was sturdy.

[cycloneye]

The mesovortices were impressive.

 https://x.com/CIRA_CSU/status/2006147642452001117

[cycloneye]

If I guess when the Melissa TCR will be out, I would say by February.

[ljmac75]

If I guess when the Melissa TCR will be out, I would say by February.

Top 10 Questions We (by "we" I mean "I") hope are answered by the Melissa TCR

1. What was up with the GFS during Melissa? The GFS kept trying to send the thing into Haiti, even when it was obviously not going there. It was pretty insistent on it for a while too.
2. Did Melissa ever go through an eyewall replacement cycle? People keep bringing up how it didn't go through an eyewall replacement cycle but had eyewall mergers or something. Hopefully we get at least a sentence or two about that part.
3. When did Melissa peak in intensity?
4. What was Melissa's peak intensity? Will the NHC bump the storm up to 165 kt? Will they move it down to 155 kt for some reason?
5. What was Melissa's landfall intensity in Jamaica?
6. Is there any other data from the core in Jamaica? Any at all. Wind, pressure, anything. Besides Josh's I mean.
7. How did it weaken so rapidly over Jamaica?
8. What was Melissa's landfall intensity in Cuba?
9. What was Melissa doing over the Bahamas? Officially making landfall I suspect.
10. When did Melissa dissipate and did it do anything of note while extratropical?

(I know we already kinda know the answer to most of these but it's not official until the TCR comes out)

[cycloneye]

Josh is going back to Jamaica and read why. I say bravo.

 https://x.com/iCyclone/status/2008623886200447414

[ljmac75]

Josh is going back to Jamaica and read why. I say bravo.

 https://x.com/iCyclone/status/2008623886200447414

 https://x.com/icyclone/status/2015880866245816437



The palm tree is still standing. Building he was in looks like it's still destroyed though, not much work.

[cycloneye]

 https://x.com/iCyclone/status/2016712589347057997



 https://x.com/iCyclone/status/2016746669543494100



 https://x.com/WeatherNation/status/2016549328811393298

[ljmac75]

He's got a few more photos of the area on his facebook. https://www.facebook.com/iCyclone/posts ... Hp8gNHbQgl

The picture of the courthouse doesn't totally do it justice, the whole top floor just... went away.

[ljmac75]

Since the Melissa TCR is the only one that has yet to come out, I thought I'd do some speculating. Not on what they'll choose for the peak intensity but the basic outline for how they would justify each potential choice:

155 kt - Max flight level winds of 172 support 150-155 kt winds at the surface. The strongest dropsonde supports 155-160 kt winds at the surface. Blend them together to get 155 kt.
160 kt - Max flight level winds of 172 support 155 kt at the surface, the strongest dropsonde supports about 157 kt at the surface. Round them up a little to account for undersampling to get 160 kt.
165 kt - 60 kt - Max flight level winds of 172 support 155 kt at the surface, the strongest dropsonde supports about 157 kt at the surface. Given substantial undersampling with a significant portion of the storm, including the eastern and northeastern eyewalls, not being sampled at all, bump up to 165 kt.
170 kt - Same as above, but with the assumption that the storm peaked earlier before recon arrived.
We all know 170 kt and 155 kt "ain't gonna happen" as they say, but it's fun to think about.

[ljmac75]

Josh "iCyclone" Morgerman gave a presentation about Melissa at the storm chaser convention, it's here around 18 minutes in [Youtube]https://www.youtube.com/watch?v=J23sA0MJP3s[/Youtube]

Not much new here, only major thing I noticed was that he discussed measuring storm surge after returning to Jamaica, said it was around 15 feet at the beach near his location. Slightly higher than forecast I think, but not by much.

[ljmac75]

Cool visuals and a nice little discussion about IR imagery from Melissa near peak intensity.

https://bsky.app/profile/jimmy-yunge.bs ... jmki2j7k2e

[cycloneye]

Posting the TCR here for any members that may want to make comments about it.

From the report.

The estimated minimum pressure of 897 mb at landfall in Jamaica is based on aircraft reconnaissance data collected before landfall, observations from the New Hope Primary School site, and data recorded by Josh Morgerman (iCyclone) in Crawford, Jamaica.

https://www.nhc.noaa.gov/data/tcr/AL132025_Melissa.pdf

[ljmac75]

Something I'm very impressed by with the TCR is the amount of the data from stations in Jamaica that was included. I did not realize the extent of the automated weather system network in Jamaica prior to the storm. The data seems very coarse (hourly pressures and 1-hour averaged winds) and it seems many stations did not survive their encounter with Melissa, but it certainly helps paint the picture.

They appear to have added some new colors to the scale specifically for Melissa in figure 9b. That's... strong. The radar image in figure 13 seems to be a picture someone took of a computer screen with their phone, which I thought was kinda funny. Very grateful for that map of Jamaica showing each parish in figure 34. I don't know where else I'd have found one of those.

Was anyone else surprised that they dropped the Cuba landfall estimate to 100 kts? Was the writing on the wall on that? I wasn't paying that close of attention to that landfall.